1. Technical Field of the Invention
The invention relates to a thermoforming station in a thermoforming machine for thermoplastic cups, which is equipped with a cyclically operating conveying section which takes over a cup sheet web from an unwinding station, the conveying section running through a heating station, the thermoforming station and further processing stations.
The field of application of the invention is the variable production of thermoplastic cups from a sheet. The thermoplastic cups receive food preparations such as cottage cheese or other milk products, pudding, jam, beverages or the like.
2. Description of the Prior Art
DE 3234506 C2 describes a thermoforming machine of the generic type mentioned. The lower die of the thermoforming station is provided with continuous cooling channels. Such a design is not possible, however, if the forming chambers for the thermoplastic cups are offset from one another.
DE 39 40 346 C1 shows the arrangement of the cooling channels within the thermoforming station, according to which the cooling channels run not only in the bottom but also in the webs between the individual forming troughs.
DE 44 18 064 C1 shows a multi-part design of the lower die of the thermoforming station. Forming troughs are inserted into an outer supporting structure, a coolant channel remaining free between supporting structure and forming trough.
U.S. Pat. No. 2,191,303 describes a die of sandwich-like construction for cooling heated plastics packaging sheets. In this construction, plates, and bars provided with milled-in coolant channels, are stacked alternately on top of one another. A cooling plate with a precisely defined through-flow is thus obtained.